function s1_generate_a_series_of_files(){
	for i in {1..100};
	do
		echo  $i> /tmp/new_files $i;
	done
}
function s2_list_4_files_in_long_format_about_account_and_group(){
	ls -l /etc/{passwd,shadow,group,gshadow} | sort -d
}
function s3_find_items_related_to_given_username(){
	grep -h "$1" /etc/{passwd,shadow} | sort -d
}
function s4_find_items_related_to_given_group_name(){
	grep -h "$1" /etc/{group,gshadow} | sort -d
}
function s5_create_groups_for_given_group_names(){
	groupadd rnd && groupadd itoperation
}
function s6_create_users_and_set_their_group_as_required(){
	useradd -G rnd adam && useradd -G rnd bob && useradd -G itoperation calvin && useradd -G itoperation david && useradd -G rnd edward
}
function s7_change_user_shell(){
	usermod -s /user/bin/sh adam && usermod -s /user/bin/sh edward
}
function s8_set_password_change_policy(){
	users=("adam" "bob" "calvin" "david" "edward")
	for user in "${users[@]}"; do
		chage -m 10 -M 60 -W 10 "$user"
	done
}
function s9_set_password_for_five_users(){
	users=("adam" "bob"  "calvin" "david" "edward")
	for ((i=0; i< 5; i++)); do
		echo "${users[i]}:${!((i+1))}" | chpasswd
	done
}
function s10_lock_bobs_password(){
	passwd -l bob
}
function s11_include_adam_into_wheel_group(){
	usermod -aG wheel adam

}
function s12_change_files_permission(){
	for ((i=3;i<= 99; i += 3)); do 
		chomd  640 "/tmp/new_files$i"
		done
}

